The present invention relates to glass fiber filtration media and, in particular glass fiber filtration media made from glass fibers that are rapidly solubilized in biological fluids.
Glass fiber filtration media are commonly used in air filtration applications. These filtration media can be classified in two groups namely, i.e. filtration media having an average efficiency between about 25% and about 60% (low efficiency filtration media) and filtration media having an average efficiency between about 65% and about 95% (intermediate and high efficiency filtration media) based on ASHRAE--52.1 test method.
While the air filtration media currently in commercial use performs well, the manufacture and/or subsequent handling of these glass fiber filtration media may result in the formation of loose fibers which can be inhaled. As it is impractical or impossible to remove such fibers from the body, it is important to make glass fiber filtration media from glass fibers having a high degree of biosolubility, i.e. fibers which are rapidly solubilized in biological fluids, while still maintaining the physical properties and performance characteristics required of such filtration media. Since the fine diameter glass fibers (glass fibers having a mean diameter between about 2.5.times.10.sup.-5 inches and about 12.0.times.10.sup.-5 inches) used in these air filtration media are normally made in a flame attenuation process, preferably, a glass composition should be used to form the fibers that can be fiberized by flame attenuation processes and still be rapidly solubilized in biological fluids.